The invention relates to a process for operating a high-pressure boiler, in particular for dry-cleaners, laundries or the like, with consuming units which are connected to a high-pressure boiler and the condensate from which is returned to a condensate tank from which, by means of a feed water pump, feed water is fed to the boiler and the condensate and feed water are fed to a heat exchanger upstream of the condensate tank.
The invention also relates to equipment (a heat exchanger) which, in particular, is suitable and intended for carrying out the process.
Any high-pressure boiler installation is provided with a condensate return. The condensate consists of the mixture of wet steam at about 105.degree. C. and a condensed hot water/steam mixture at about 90.degree.-100.degree. C.
The hot condensate is normally collected again in a condensate tank of the boiler installation. The boiler feed water pump then forces this hot water back into the superheated steam boiler, where renewed vaporisation takes place. Since water above 80.degree.-85.degree. C. causes difficulties with the pumps in the boiler, either very large condensate tanks are provided or the condensate is cooled additionally. On the other hand, this leads again to difficulties if the condensate is unduly cold (for example 60.degree. C.), since soot then deposits on the boiler heating surfaces or boiler heating lines. It is also known to provide the condensate tanks with an exit gas branch, through which the wet steam can escape. It is the purpose of all these measures to cool down the very hot condensate, if possible, so that a condensate temperature of 60.degree.-70.degree. C. upstream of the pump is ensured.
High heat losses are incurred in such superheated steam boilers. A boiler unit of this type also requires a long running-up period on start-up, until the superheated steam has reached its necessary temperature.